In a three-dimensional shaping method, the thickness of each multilayer unit is constant in most cases.
In actuality, in Patent Document 1, although consideration is given to the optimization of the thickness of the outermost surface layer in three-dimensional shaping, the thickness is not changed for each multilayer unit.
However, Patent Document 2 discloses that, when in a multilayer operation in a predetermined stage, a convex portion exceeding the thickness of multilayers is detected, the thickness of multilayers in the subsequent stage is set to exceed the height of the convex portion.
However, in the setting of the thickness as described above, the thickness is not selected based on unified criteria corresponding to the overall shape of a shaped object.
In actual three-dimensional shaping, a variation in the cross-sectional shape of a shaped object in a horizontal direction, that is, a direction perpendicular to a height direction in which a multilayer operation is performed and the thickness of each multilayer unit are closely connected with each other.
Specifically, when the shape of each multilayer cross section is significantly varied along the height direction, the thickness of each multilayer unit is decreased such that the original shape of the shaped object can be accurately realized whereas when only a slight variation in the thickness along the up/down direction is produced, even if the thickness of each multilayer unit is set larger, the original shape of the shaped object does not necessarily become inaccurate.
However, in a conventional technique, no consideration is given to the appropriate setting of the thickness of each multilayer unit according to the variation conditions of the cross section in the horizontal direction along the up/down direction.